On Wed, Sep 12, 2018 at 05:08:52PM +0200, Arnd Bergmann wrote: > The .ioctl and .compat_ioctl file operations have the same prototype so > they can both point to the same function, which works great almost all > the time when all the commands are compatible. > > One exception is the s390 architecture, where a compat pointer is only > 31 bit wide, and converting it into a 64-bit pointer requires calling > compat_ptr(). Most drivers here will ever run in s390, but since we now > have a generic helper for it, it's easy enough to use it consistently. > > I double-checked all these drivers to ensure that all ioctl arguments > are used as pointers or are ignored, but are not interpreted as integer > values. > > Signed-off-by: Arnd Bergmann <arnd at arndb.de> > --- ... > drivers/platform/x86/wmi.c | 2 +- ... > static void link_event_work(struct work_struct *work) > diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c > index 04791ea5d97b..e4d0697e07d6 100644 > --- a/drivers/platform/x86/wmi.c > +++ b/drivers/platform/x86/wmi.c > @@ -886,7 +886,7 @@ static const struct file_operations wmi_fops = { > .read = wmi_char_read, > .open = wmi_char_open, > .unlocked_ioctl = wmi_ioctl, > - .compat_ioctl = wmi_ioctl, > + .compat_ioctl = generic_compat_ioctl_ptrarg, > }; For platform/drivers/x86: Acked-by: Darren Hart (VMware) <dvhart at infradead.org> As for a longer term solution, would it be possible to init fops in such a way that the compat_ioctl call defaults to generic_compat_ioctl_ptrarg so we don't have to duplicate this boilerplate for every ioctl fops structure? -- Darren Hart VMware Open Source Technology Center